Not everybody who has type 1 diabetes is automatically thin. There are some children and adolescents with type 1 diabetes that are overweight. Why is this? What can be done about it? Professor Martin Wabitsch, expert on diabetes and obesity, has the answers. 

Professor Martin Wabitsch is a researcher in the fields of diabetology and adiposity. He is Head of the Paediatric Endocrinology and Diabetology Department at the University of Ulm, and in charge of the outpatient clinic for Interdisciplinary Treatment of Obesity. Professor Wabitsch is examining the growth and function of fatty tissue and is trying to find out how to prevent overweight in children and adolescents.  

DPJ: Some children with type 1 diabetes become overweight, and some don’t? Are there any figures?

Prof Wabitsch: There are no official numbers, at least not in the German-speaking countries. We only know that, according to the National Health Survey, 15% of all children and adolescents in Germany are overweight and that 6.3% of these are obese, i.e., pathologically overweight. The figures for diabetes are probably similar, although there are indications that they are slightly higher—at least in those who have good metabolic control. This applies mainly to girls.

DPJ: Does your experience confirm this?

Prof Wabitsch: Yes. I see this in my clinic. In fact, by merely observing how much a child has put on since their last visit I can judge, even before actually having to open their diabetes log book or measure the HbA1c, whether their metabolic control has been good or bad.  

DPJ: And if the child has put on weight ... 

Prof Wabitsch: ... this is, actually, a good sign. Herein lies the conflict: When metabolic control improves, the child puts on weight. This is bad news, especially for girls. Girls, in particular, tend to have an increased fear of putting on too much weight and, consequently, stop taking insulin and eating regularly. There are even cases in which girls knowingly carry a significantly elevated HbA1c, just to stay thin. As a result, they may look sporty and attractive, but do so at the expense of their metabolic health.  

DPJ: What do you suggest when a girls says, “I’m too fat.”?

Prof Wabitsch: Firstly, she must be brought to accept that metabolic health takes priority and know as to why this is. Secondly, we suggest something that we apply to all children and adolescents. One has to make clear that insulin is not the only factor that influences weight: Exercise and good nourishment are the classical key players. Physical exercise of around one hour a day is essential in building muscle mass, reducing fat mass, and positively influencing the metabolism. The other key players are caloric intake and nutrition. The need to eat well, with moderate fat intake, applies to all. Complex carbohydrates—slow to digest and high in fibre—are recommended when possible. They take longer to enter the bloodstream and maintain the feeling of fullness longer. 
Although pure sugar is not forbidden, it should be handled with utmost caution. One should avoid pure, refined sugar, or foods high in sugar content as much as possible. No level of insulin therapy can manage excess sugar intake, and weight gain is the result. 

DPJ: What role does insulin play?

Prof Wabitsch: Epidemiological data show conclusively that there are factors that will lead to overweight in type 1 diabetes: irregular insulin administration combined with irregular eating habits and, interestingly, many daily insulin injections. People with type 1 diabetes who use the modern analogue insulins and inject four or five times a day are higher in weight than those who inject fewer. This affects girls more than boys—perhaps due to a difference in their eating and exercise habits during puberty. In any case, irregularity in eating habits is a sure way to gain weight. One temporarily loses weight, only to put it straight back on. 
Because insulin affects the nervous system and steers feelings of hunger and fullness, irregular eating habits throw this delicate system out of kilter. Playing around with the levels of insulin always seems to cause weight gain in some way.  

DPJ: Is there a difference between injecting insulin or using a pump in terms of weight gain?

Prof Wabitsch: This hasn’t been definitively established as yet. We only know that, with pump therapy, much less insulin is necessary to achieve metabolic control. In my opinion, we need more verification until we can say with confidence whether one can control weight better or not with a pump.

DPJ: When would you personally advise the use of a pump?

Prof Wabitsch: First of all, one should always fall back on the traditional exercise and diet regime. This means, for instance, parents and children working together to overcome the fear of sport-related hypoglycaemia by learning how to adjust insulin amounts. Secondly, eating preferences should be looked at. It would be wrong to adjust eating habits according to a fixed insulin regime. I prefer it when the patient tells me about his or her normal eating habits. If these fail to fit around the usual three-meals-a-day pattern, I tend to suggest the use of a pump. The others should be very well aware of what they eat and how many fat calories they consume—not all fatty snacks require additional insulin. 
People with type 1 diabetes tend to eat less healthily than their non-diabetic peers, maybe because they want to avoid always having to calculate insulin dosages. 

DPJ: Can an underactive thyroid gland cause overweight?

Prof Wabitsch: Yes. This is the cause of overweight in a proportion of the population. The annual screening programme has indicated to me, however, that this is not so relevant in Germany. Hypothyroidism is not usually an issue in the patients I see.

DPJ: What do you do about the ‘good’ and ‘bad’ consumers?

Prof Wabitsch: All in all, weight is mostly hereditary. The individual cannot alter this fact. People with diabetes must, however, accept that good metabolic control is usually accompanied by a weight factor.

DPJ: How do you adjust the therapy to weight loss?

Prof Wabitsch: It is of great importance to write down a dietary plan, and to be aware of just how much weight is intended to be lost. Within the first few days of a weight-loss programme, one needs much less insulin. This is a critical phase that should be closely supervised by a diabetologist, as the chance of hypoglycaemia is increased. Many larger departments offer not only education programmes in diabetes, but also in obesity. There is no reason why children and adolescents with type 1 diabetes should not participate the latter as well. It would be ideal to have a combined education programme for this particular group, as one can achieve more in a group than individually. We, in Ulm, take elements from our obesity group and integrate these into our type 1 diabetes group. We are presently, however, working at creating a special new group for obesity and type 1 diabetes together. 

DPJ: Do you have any tips for the calorie-rich Christmas period?

Prof Wabitsch: Exceptions are always possible. On these particular days, one does need to measure blood sugar a little more often. But one should also be a little, shall we say, realistic. Christmas is an annual festival which brings family and community together. Having said that, I would hope that the family try to nourish themselves as healthily as possible (if not out of solidarity!). 
In any case, the parents’ example is very, very important for children with type 1 diabetes.

Professor Martin Wabitsch MD
Paediatric Specialist
Diabetology DDG
Paediatric Clinic, University of Ulm
E-mail: Martin.Wabitsch(at)uniklinik-ulm(dot)de

Interview: Nicole Finkenauer-Ganz